Dark matter, a mysterious substance that makes up about 95% of the mass of our galaxy, is invisible and does not interact with light. However, a new study proposes a way that the influence of dark matter on our solar system could be directly observed with a future experiment.
To study the influence, Edward Belbruno, lead author of the study, calculated the galactic force, the general gravitational force of normal matter combined with dark matter throughout the galaxy, and found that about 45% of this force in our solar system is dark matter and 55% is normal matter, called baryonic matter.
“We predict that if you get far enough out in the solar system, you actually have a chance to start measuring the strength of dark matter. This is the first idea of how to do it and where we would do it,” said Jim. Green, a co-author of the study and an adviser to NASA’s Office of the Chief Scientist.
As far as its influence is concerned, the study authors predict that dark matter gravity interacts very slightly with all spacecraft that the US space agency NASA has sent on paths leading out of the solar system, including the retired Pioneer probes. 10 and 11.
“But it is a tiny effect. After traveling billions of miles, the path of a spacecraft like Pioneer 10 would only be off about 1.6 meters (5 feet) due to the influence of dark matter. They feel the effect of dark matter, but it’s so small that we can’t measure it,” Green explained.
According to the authors, dark matter would also influence the orbit of a giant planet in the far reaches of the solar system, a hypothetical object dubbed “Planet 9 or Planet X” that scientists have been searching for in recent years. If the hypothetical Neptune-sized planet exists, dark matter could perhaps even push it away from the area where scientists are currently looking for it.
The article is published in Monthly Notices of the Royal Astronomical Society